The invention relates to an installation for the telephone transmission of conversations between interlocutors in a noisy environment.
It is a difficult problem to provide a telephonic transmission between interlocutors speaking in a noisy environment. The microphone located in the vicinity of the mouth of one interlocutor receives in fact permanently the environment noise. The earphone or head set with which the other of the interlocutors is provided reproduces the noise collected by the microphone which adds to the noise with which it is himself surrounded.
It is this reason why there has been proposed an installation wherein each of the interlocutors has a switch allowing him at will to isolate his telephone receiver from the microphone or microphones to which the latter is connected. But the manipulation of this switch via a knob or similar calls for manual intervention. In some cases, the intervention is such a constraint that the user prefers to block his switch in the transmission position rather than calling upon one of his hands, particularly when the missions he has to accomplish are delicate and have to be carried out almost instantaneously. But then, the reception by the telephone receiver of the ambient noise collected by the microphone represents a discomfort which, in the long run, may become intolerable.